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Phangwiwat T, Phunchongharn P, Wongsawat Y, Chatnuntawech I, Wang S, Chunharas C, Sprague TC, Woodman GF, Itthipuripat S. Sustained attention operates via dissociable neural mechanisms across different eccentric locations. Sci Rep 2024; 14:11188. [PMID: 38755251 PMCID: PMC11099062 DOI: 10.1038/s41598-024-61171-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2023] [Accepted: 05/02/2024] [Indexed: 05/18/2024] Open
Abstract
In primates, foveal and peripheral vision have distinct neural architectures and functions. However, it has been debated if selective attention operates via the same or different neural mechanisms across eccentricities. We tested these alternative accounts by examining the effects of selective attention on the steady-state visually evoked potential (SSVEP) and the fronto-parietal signal measured via EEG from human subjects performing a sustained visuospatial attention task. With a negligible level of eye movements, both SSVEP and SND exhibited the heterogeneous patterns of attentional modulations across eccentricities. Specifically, the attentional modulations of these signals peaked at the parafoveal locations and such modulations wore off as visual stimuli appeared closer to the fovea or further away towards the periphery. However, with a relatively higher level of eye movements, the heterogeneous patterns of attentional modulations of these neural signals were less robust. These data demonstrate that the top-down influence of covert visuospatial attention on early sensory processing in human cortex depends on eccentricity and the level of saccadic responses. Taken together, the results suggest that sustained visuospatial attention operates differently across different eccentric locations, providing new understanding of how attention augments sensory representations regardless of where the attended stimulus appears.
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Affiliation(s)
- Tanagrit Phangwiwat
- Neuroscience Center for Research and Innovation (NX), Learning Institute, King Mongkut's University of Technology Thonburi (KMUTT), Bangkok, 10140, Thailand
- Big Data Experience Center (BX), King Mongkut's University of Technology Thonburi (KMUTT), Bangkok, 10600, Thailand
- Department of Computer Engineering, King Mongkut's University of Technology Thonburi (KMUTT), Bangkok, 10140, Thailand
| | - Phond Phunchongharn
- Big Data Experience Center (BX), King Mongkut's University of Technology Thonburi (KMUTT), Bangkok, 10600, Thailand
- Department of Computer Engineering, King Mongkut's University of Technology Thonburi (KMUTT), Bangkok, 10140, Thailand
| | - Yodchanan Wongsawat
- Department of Biomedical Engineering, Faculty of Engineering, Mahidol University, Nakhon Pathom, 73170, Thailand
| | - Itthi Chatnuntawech
- National Nanotechnology Center, National Science and Technology Development Agency, Pathum Thani, 12120, Thailand
| | - Sisi Wang
- Department of Experimental and Applied Psychology, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
- Department of Psychology, Vanderbilt University, Nashville, TN, 37235, USA
| | - Chaipat Chunharas
- Cognitive Clinical and Computational Neuroscience Center of Excellence, Department of Internal Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, 10330, Thailand
- Chula Neuroscience Center, King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, 10330, Thailand
| | - Thomas C Sprague
- Department of Psychological and Brain Sciences, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Geoffrey F Woodman
- Department of Psychology, Vanderbilt University, Nashville, TN, 37235, USA
| | - Sirawaj Itthipuripat
- Neuroscience Center for Research and Innovation (NX), Learning Institute, King Mongkut's University of Technology Thonburi (KMUTT), Bangkok, 10140, Thailand.
- Big Data Experience Center (BX), King Mongkut's University of Technology Thonburi (KMUTT), Bangkok, 10600, Thailand.
- Department of Psychology, Vanderbilt University, Nashville, TN, 37235, USA.
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Tian M, Ji Y, Wang R, Bi HY. Impaired Ability in Visual-Spatial Attention in Chinese Children With Developmental Dyslexia. JOURNAL OF LEARNING DISABILITIES 2024:222194241241040. [PMID: 38591175 DOI: 10.1177/00222194241241040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/10/2024]
Abstract
A growing body of evidence suggests that children with dyslexia in alphabetic languages exhibit visual-spatial attention deficits that can obstruct reading acquisition by impairing their phonological decoding skills. However, it remains an open question whether these visual-spatial attention deficits are present in children with dyslexia in non-alphabetic languages. Chinese, with its logographic writing system, offers a unique opportunity to explore this question. The presence of visual-spatial attention deficits in Chinese children with dyslexia remains insufficiently investigated. Therefore, this study aimed to explore whether such deficits exist, employing a visual search paradigm. Three visual search tasks were conducted, encompassing two singleton feature search tasks and a serial conjunction search task. The results indicated that Chinese children with dyslexia performed as well as chronological age-matched control children in color search tasks but less effectively in orientation search, suggesting a difficulty in the rapid visual processing of orientation: a deficit potentially specific to Chinese dyslexia. Crucially, Chinese children with dyslexia also exhibited lower accuracy, longer reaction times, and steeper slopes in the reaction times by set size function in the conjunction search task compared to control children, which is indicative of a visual-spatial attention deficit.
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Affiliation(s)
- Mengyu Tian
- CAS Key Laboratory of Behavioral Science, Center for Brain Science and Learning Difficulties, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
- Center for Educational Science and Technology, Institute of Advanced Studies in Humanities and Social Sciences, Beijing Normal University, Zhuhai, China
| | - Yuzhu Ji
- Institute of Applied Psychology, College of Education, Zhejiang University of Technology, Hangzhou, China
| | - Runzhou Wang
- CAS Key Laboratory of Behavioral Science, Center for Brain Science and Learning Difficulties, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Hong-Yan Bi
- CAS Key Laboratory of Behavioral Science, Center for Brain Science and Learning Difficulties, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
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3
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Di Dona G, Ronconi L. Beta oscillations in vision: a (preconscious) neural mechanism for the dorsal visual stream? Front Psychol 2023; 14:1296483. [PMID: 38155693 PMCID: PMC10753839 DOI: 10.3389/fpsyg.2023.1296483] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Accepted: 11/15/2023] [Indexed: 12/30/2023] Open
Abstract
Neural oscillations in alpha (8-12 Hz) and beta (13-30 Hz) frequency bands are thought to reflect feedback/reentrant loops and large-scale cortical interactions. In the last decades a main effort has been made in linking perception with alpha-band oscillations, with converging evidence showing that alpha oscillations have a key role in the temporal and featural binding of visual input, configuring the alpha rhythm a key determinant of conscious visual experience. Less attention has been historically dedicated to link beta oscillations and visual processing. Nonetheless, increasing studies report that task conditions that require to segregate/integrate stimuli in space, to disentangle local/global shapes, to spatially reorganize visual inputs, and to achieve motion perception or form-motion integration, rely on the activity of beta oscillations, with a main hub in parietal areas. In the present review, we summarize the evidence linking oscillations within the beta band and visual perception. We propose that beta oscillations represent a neural code that supports the functionality of the magnocellular-dorsal (M-D) visual pathway, serving as a fast primary neural code to exert top-down influences on the slower parvocellular-ventral visual pathway activity. Such M-D-related beta activity is proposed to act mainly pre-consciously, providing the spatial coordinates of vision and guiding the conscious extraction of objects identity that are achieved with slower alpha rhythms in ventral areas. Finally, within this new theoretical framework, we discuss the potential role of M-D-related beta oscillations in visuo-spatial attention, oculo-motor behavior and reading (dis)abilities.
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Affiliation(s)
- Giuseppe Di Dona
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
- School of Psychology, Vita-Salute San Raffaele University, Milan, Italy
| | - Luca Ronconi
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
- School of Psychology, Vita-Salute San Raffaele University, Milan, Italy
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Lawton T, Shelley-Tremblay J, Huang MX. Case report: Neural timing deficits prevalent in developmental disorders, aging, and concussions remediated rapidly by movement discrimination exercises. Front Neurol 2023; 14:898781. [PMID: 37818220 PMCID: PMC10560731 DOI: 10.3389/fneur.2023.898781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 09/04/2023] [Indexed: 10/12/2023] Open
Abstract
Background The substantial evidence that neural timing deficits are prevalent in developmental disorders, aging, and concussions resulting from a Traumatic Brain Injury (TBI) is presented. Objective When these timing deficits are remediated using low-level movement-discrimination training, then high-level cognitive skills, including reading, attention, processing speed, problem solving, and working memory improve rapidly and effectively. Methods In addition to the substantial evidence published previously, new evidence based on a neural correlate, MagnetoEncephalography physiological recordings, on an adult dyslexic, and neuropsychological tests on this dyslexic subject and an older adult were measured before and after 8-weeks of contrast sensitivity-based left-right movement-discrimination exercises were completed. Results The neuropsychological tests found large improvements in reading, selective and sustained attention, processing speed, working memory, and problem-solving skills, never before found after such a short period of training. Moreover, these improvements were found 4 years later for older adult. Substantial MEG signal increases in visual Motion, Attention, and Memory/Executive Control Networks were observed following training on contrast sensitivity-based left-right movement-discrimination. Improving the function of magnocells using figure/ground movement-discrimination at both low and high levels in dorsal stream: (1) improved both feedforward and feedback pathways to modulate attention by enhancing coupled theta/gamma and alpha/gamma oscillations, (2) is adaptive, and (3) incorporated cycles of feedback and reward at multiple levels. Conclusion What emerges from multiple studies is the essential role of timing deficits in the dorsal stream that are prevalent in developmental disorders like dyslexia, in aging, and following a TBI. Training visual dorsal stream function at low levels significantly improved high-level cognitive functions, including processing speed, selective and sustained attention, both auditory and visual working memory, problem solving, and reading fluency. A paradigm shift for treating cognitive impairments in developmental disorders, aging, and concussions is crucial. Remediating the neural timing deficits of low-level dorsal pathways, thereby improving both feedforward and feedback pathways, before cognitive exercises to improve specific cognitive skills provides the most rapid and effective methods to improve cognitive skills. Moreover, this adaptive training with substantial feedback shows cognitive transfer to tasks not trained on, significantly improving a person's quality of life rapidly and effectively.
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Affiliation(s)
- Teri Lawton
- Cognitive Neuroscience, Perception Dynamics Institute, Encinitas, CA, United States
| | | | - Ming-Xiong Huang
- Radiology Imaging Laboratory, Department of Radiology, University of California, San Diego, San Diego, CA, United States
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Di Pietro SV, Willinger D, Frei N, Lutz C, Coraj S, Schneider C, Stämpfli P, Brem S. Disentangling influences of dyslexia, development, and reading experience on effective brain connectivity in children. Neuroimage 2023; 268:119869. [PMID: 36639004 DOI: 10.1016/j.neuroimage.2023.119869] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 12/29/2022] [Accepted: 01/09/2023] [Indexed: 01/12/2023] Open
Abstract
Altered brain connectivity between regions of the reading network has been associated with reading difficulties. However, it remains unclear whether connectivity differences between children with dyslexia (DYS) and those with typical reading skills (TR) are specific to reading impairments or to reading experience. In this functional MRI study, 132 children (M = 10.06 y, SD = 1.46) performed a phonological lexical decision task. We aimed to disentangle (1) disorder-specific from (2) experience-related differences in effective connectivity and to (3) characterize the development of DYS and TR. We applied dynamic causal modeling to age-matched (ndys = 25, nTR = 35) and reading-level-matched (ndys = 25, nTR = 22) groups. Developmental effects were assessed in beginning and advanced readers (TR: nbeg = 48, nadv = 35, DYS: nbeg = 24, nadv = 25). We show that altered feedback connectivity between the inferior parietal lobule and the visual word form area (VWFA) during print processing can be specifically attributed to reading impairments, because these alterations were found in DYS compared to both the age-matched and reading-level-matched TR. In contrast, feedforward connectivity from the VWFA to parietal and frontal regions characterized experience in TR and increased with age and reading skill. These directed connectivity findings pinpoint disorder-specific and experience-dependent alterations in the brain's reading network.
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Affiliation(s)
- Sarah V Di Pietro
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of Zurich, Switzerland; Neuroscience Center Zurich, University of Zurich and ETH Zurich, Switzerland; URPP Adaptive Brain Circuits in Development and Learning (AdaBD), University of Zurich, Zurich, Switzerland
| | - David Willinger
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of Zurich, Switzerland; Neuroscience Center Zurich, University of Zurich and ETH Zurich, Switzerland; Department of Psychology and Psychodynamics, Karl Landsteiner University of Health Sciences, Krems an der Donau, Austria
| | - Nada Frei
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of Zurich, Switzerland; Neuroscience Center Zurich, University of Zurich and ETH Zurich, Switzerland
| | - Christina Lutz
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of Zurich, Switzerland; Neuroscience Center Zurich, University of Zurich and ETH Zurich, Switzerland
| | - Seline Coraj
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of Zurich, Switzerland; Neuroscience Center Zurich, University of Zurich and ETH Zurich, Switzerland
| | - Chiara Schneider
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of Zurich, Switzerland
| | - Philipp Stämpfli
- MR-Center of the Department of Psychiatry, Psychotherapy and Psychosomatics and the Department of Child and Adolescent Psychiatry and Psychotherapy, Psychiatric Hospital, University of Zurich, Zurich, Switzerland
| | - Silvia Brem
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of Zurich, Switzerland; Neuroscience Center Zurich, University of Zurich and ETH Zurich, Switzerland; URPP Adaptive Brain Circuits in Development and Learning (AdaBD), University of Zurich, Zurich, Switzerland; MR-Center of the Department of Psychiatry, Psychotherapy and Psychosomatics and the Department of Child and Adolescent Psychiatry and Psychotherapy, Psychiatric Hospital, University of Zurich, Zurich, Switzerland.
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6
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Gu H, Chen H, Yao Q, Wang S, Ding Z, Yuan Z, Zhao X, Li X. Cortical theta-gamma coupling tracks the mental workload as an indicator of mental schema development during simulated quadrotor UAV operation. J Neural Eng 2022; 19. [PMID: 36541548 DOI: 10.1088/1741-2552/aca5b6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Accepted: 11/24/2022] [Indexed: 11/25/2022]
Abstract
Objective. In the emerging field of neuroergonomics, mental workload assessment is one of the most important problems. Previous studies have made some progress on the relationship between task difficulties and mental workload, but how the mental schema, a reflection of the understanding and mastery degree of a task, affects mental workload has not been clearly discussed.Approach. There is emerging appreciation for the role of theta-gamma coupling (TGC) in high-level cognitive functions. Here, we attempt to further our understanding of how mental schema development and task difficulty had an impact on mental workload from the perspective of TGC. Specifically, the variation of TGC coupling strength and coupling pattern was estimated with different test orders and task difficulties performed by 51 students in a ten-day simulated quadrotor unmanned aerial vehicle flight training and test tasks.Main results. During the training, TGC increased with mental schema development. For the test tasks, TGC did not change with increasing task difficulty before the operator formed a mental schema but decreased with the increasing mental workload after the formation of the mental schema.Significance. Our results suggest that TGC was a robust indicator of mental schema development and could be biased by task difficulty. In conclusion, TGC can be a promising measure of mental workload, but only for experienced operators.
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Affiliation(s)
- Heng Gu
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, People's Republic of China
| | - He Chen
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, People's Republic of China.,School of Systems Science, Beijing Normal University, Beijing, People's Republic of China
| | - Qunli Yao
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, People's Republic of China
| | - Shaodi Wang
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, People's Republic of China
| | - Zhaohuan Ding
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, People's Republic of China
| | - Ziqian Yuan
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, People's Republic of China
| | - Xiaochuan Zhao
- Institute of Computer Applied Technology of China North Industries Group Corporation Limited, Beijing, People's Republic of China
| | - Xiaoli Li
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, People's Republic of China
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7
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Valdois S. The visual-attention span deficit in developmental dyslexia: Review of evidence for a visual-attention-based deficit. DYSLEXIA (CHICHESTER, ENGLAND) 2022; 28:397-415. [PMID: 35903834 DOI: 10.1002/dys.1724] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 04/07/2022] [Accepted: 07/13/2022] [Indexed: 06/15/2023]
Abstract
The visual attention span (VAS) deficit hypothesis in developmental dyslexia posits that a subset of dyslexic individuals shows a multielement parallel processing deficit due to reduced visual attention capacity. However, the attention-based interpretation of poor performance on VAS tasks is hotly debated. The purpose of the present paper is to clarify this issue through a critical review of relevant behavioural and neurobiological findings. We first examine the plausibility of alternative verbal interpretations of VAS performance, evaluating whether performance on VAS tasks might reflect verbal short-term memory, verbal coding or visual-to-verbal mapping skills. We then focus on the visual dimensions of VAS tasks to question whether VAS primarily reflects visuo-attentional rather than more basic visual skills. Scrutiny of the available behavioural and neurobiological findings not only points to a deficit of visual attention in dyslexic individuals with impaired VAS but further suggests a selective endogenous attentional system deficit that relates to atypical functioning of the brain dorsal attentional network. The overview clarifies the debate on what is being measured through VAS tasks and provides insights on how to interpret the VAS deficit in developmental dyslexia.
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Sheldon AD, Kafadar E, Fisher V, Greenwald MS, Aitken F, Negreira AM, Woods SW, Powers AR. Perceptual pathways to hallucinogenesis. Schizophr Res 2022; 245:77-89. [PMID: 35216865 PMCID: PMC9232894 DOI: 10.1016/j.schres.2022.02.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 01/31/2022] [Accepted: 02/02/2022] [Indexed: 12/22/2022]
Abstract
Recent advances in computational psychiatry have provided unique insights into the neural and cognitive underpinnings of psychotic symptoms. In particular, a host of new data has demonstrated the utility of computational frameworks for understanding how hallucinations might arise from alterations in typical perceptual processing. Of particular promise are models based in Bayesian inference that link hallucinatory perceptual experiences to latent states that may drive them. In this piece, we move beyond these findings to ask: how and why do these latent states arise, and how might we take advantage of heterogeneity in that process to develop precision approaches to the treatment of hallucinations? We leverage specific models of Bayesian inference to discuss components that might lead to the development of hallucinations. Using the unifying power of our model, we attempt to place disparate findings in the study of psychotic symptoms within a common framework. Finally, we suggest directions for future elaboration of these models in the service of a more refined psychiatric nosology based on predictable, testable, and ultimately treatable information processing derangements.
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Affiliation(s)
- Andrew D Sheldon
- Yale University School of Medicine and the Connecticut Mental Health Center, New Haven, CT, United States of America
| | - Eren Kafadar
- Yale University School of Medicine and the Connecticut Mental Health Center, New Haven, CT, United States of America
| | - Victoria Fisher
- Yale University School of Medicine and the Connecticut Mental Health Center, New Haven, CT, United States of America
| | - Maximillian S Greenwald
- Yale University School of Medicine and the Connecticut Mental Health Center, New Haven, CT, United States of America
| | - Fraser Aitken
- School of Biomedical and Imaging Sciences, Kings College, London, UK
| | | | - Scott W Woods
- Yale University School of Medicine and the Connecticut Mental Health Center, New Haven, CT, United States of America
| | - Albert R Powers
- Yale University School of Medicine and the Connecticut Mental Health Center, New Haven, CT, United States of America.
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Leung TW, Cheong AMY, Chan HHL. Deficits in the Magnocellular Pathway of People with Reading Difficulties. CURRENT DEVELOPMENTAL DISORDERS REPORTS 2022. [DOI: 10.1007/s40474-022-00248-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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10
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Dynamic coupling of oscillatory neural activity and its roles in visual attention. Trends Neurosci 2022; 45:323-335. [DOI: 10.1016/j.tins.2022.01.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 12/20/2021] [Accepted: 01/24/2022] [Indexed: 11/17/2022]
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11
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Romanovska L, Bonte M. How Learning to Read Changes the Listening Brain. Front Psychol 2021; 12:726882. [PMID: 34987442 PMCID: PMC8721231 DOI: 10.3389/fpsyg.2021.726882] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 11/23/2021] [Indexed: 01/18/2023] Open
Abstract
Reading acquisition reorganizes existing brain networks for speech and visual processing to form novel audio-visual language representations. This requires substantial cortical plasticity that is reflected in changes in brain activation and functional as well as structural connectivity between brain areas. The extent to which a child's brain can accommodate these changes may underlie the high variability in reading outcome in both typical and dyslexic readers. In this review, we focus on reading-induced functional changes of the dorsal speech network in particular and discuss how its reciprocal interactions with the ventral reading network contributes to reading outcome. We discuss how the dynamic and intertwined development of both reading networks may be best captured by approaching reading from a skill learning perspective, using audio-visual learning paradigms and longitudinal designs to follow neuro-behavioral changes while children's reading skills unfold.
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Affiliation(s)
| | - Milene Bonte
- *Correspondence: Linda Romanovska, ; Milene Bonte,
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12
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Pina Rodrigues A, Castelo-Branco M, van Asselen M. Disrupted Spatial Organization of Cued Exogenous Attention Persists Into Adulthood in Developmental Dyslexia. Front Psychol 2021; 12:769237. [PMID: 34867673 PMCID: PMC8634137 DOI: 10.3389/fpsyg.2021.769237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 10/06/2021] [Indexed: 12/03/2022] Open
Abstract
Purpose: Abnormal exogenous attention orienting and diffused spatial distribution of attention have been associated with reading impairment in children with developmental dyslexia. However, studies in adults have failed to replicate such relationships. The goal of the present study was to address this issue by assessing exogenous visual attention and its peripheral spatial distribution in adults with developmental dyslexia. Methods: We measured response times, accuracy and eye movements of 18 dyslexics and 19 typical readers in a cued discrimination paradigm, in which stimuli were presented at different peripheral eccentricities. Results: Results showed that adults with developmental dyslexia were slower that controls in using their mechanisms of exogenous attention orienting. Moreover, we found that while controls became slower with the increase of eccentricity, dyslexics showed an abnormal inflection at 10° as well as similar response times at the most distant eccentricities. Finally, dyslexics show attentional facilitation deficits above 12° of eccentricity, suggesting an attentional engagement deficit at far periphery. Conclusion: Taken together, our findings indicate that, in dyslexia, the temporal deficits in orientation of attention and its abnormal peripheral spatial distribution are not restricted to childhood and persist into adulthood. Our results are, therefore, consistent with the hypothesis that the neural network underlying selective spatial attention is disrupted in dyslexia.
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Affiliation(s)
- Ana Pina Rodrigues
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute of Nuclear Sciences Applied to Health, University of Coimbra, Coimbra, Portugal
| | - Miguel Castelo-Branco
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute of Nuclear Sciences Applied to Health, University of Coimbra, Coimbra, Portugal.,Faculty of Medicine, University of Coimbra, Coimbra, Portugal
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13
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Vialatte A, Salemme R, Khan AZ, Pisella L. Attentional limits in visual search with and without dorsal parietal dysfunction: space-based window or object-based span? Neuropsychologia 2021; 161:108013. [PMID: 34474063 DOI: 10.1016/j.neuropsychologia.2021.108013] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 07/15/2021] [Accepted: 08/26/2021] [Indexed: 10/20/2022]
Abstract
Attentional resource and distribution are specifically impaired in simultanagnosia, and also in the visuo-attentional form of developmental dyslexia. Both clinical conditions are conceived as a limitation of simultaneous visual processing after superior parietal lobule (SPL) dysfunction (review in Valdois et al., 2019). However, a reduced space-based attentional window (i.e. a limited visual eccentricity at which the target object can be identified, Khan et al. 2016) has been demonstrated in simultanagnosia versus a reduced object-based span (i.e. a limited number of objects processed at each fixation, Bosse et al., 2007) in developmental dyslexia. In healthy individuals, the cost in reaction times per item in serial search tasks suggests that a group of objects is processed simultaneously at a time, but this group is also undefined and depends on the visual complexity of the task. Healthy individuals and a patient with simultanagnosia performed serial search tasks involving either symbols (made of separable features) or objects made of non-separable features, and with distractors that were either all identical or all dissimilar. We used a moving window paradigm to determine whether the task was performed with a "working space" versus a "working span" limitation in control group and in patient with bilateral SPL damage. We found that healthy individuals performed search in a color task comprising non-separable feature objects and dissimilar distractors with a limited space-based attentional window; this attentional window, as well as the mean saccade amplitude used to displace it across the visual display, were independent of set size, thus inconsistent with an object-based attentional span. In the symbol task comprising a feature-absent search in which all feature-present distractors were dissimilar, we observed that mean saccade amplitude decreased with set size and that search performance could not be mimicked by a moving window of a single diameter; instead participants seemed to process a fixed number of symbols at a time (object-based span). Following bilateral SPL lesions, patient IG demonstrated a similar space-based search process in the color search task with a normal attentional window. In contrast, her cost-per-item in the symbol task increased dramatically, demonstrating a clear deficit of simultaneous object perception. These results confirmed the specific contribution of the SPL to the visual processing of multiple objects made of separable features (like letters), and more dramatically when they are all different, which explains the specific difficulty for a reading beginner in case of SPL dysfunction.
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Affiliation(s)
- Audrey Vialatte
- Lyon Neuroscience Research Center (CRNL), Trajectoires Team, INSERM U1028, CNRS UMR, 5292, Université Claude Bernard, Lyon, France
| | - Romeo Salemme
- Lyon Neuroscience Research Center (CRNL), Trajectoires Team, INSERM U1028, CNRS UMR, 5292, Université Claude Bernard, Lyon, France
| | - Aarlenne Zein Khan
- Lyon Neuroscience Research Center (CRNL), Trajectoires Team, INSERM U1028, CNRS UMR, 5292, Université Claude Bernard, Lyon, France; School of Optometry, University of Montreal, Montreal, Canada
| | - Laure Pisella
- Lyon Neuroscience Research Center (CRNL), Trajectoires Team, INSERM U1028, CNRS UMR, 5292, Université Claude Bernard, Lyon, France.
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14
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Kershner JR. Multisensory deficits in dyslexia may result from a locus coeruleus attentional network dysfunction. Neuropsychologia 2021; 161:108023. [PMID: 34530025 DOI: 10.1016/j.neuropsychologia.2021.108023] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 08/06/2021] [Accepted: 09/11/2021] [Indexed: 12/13/2022]
Abstract
A fundamental educational requirement of beginning reading is to learn, access, and rapidly process associations between novel visuospatial symbols and their phonological representations in speech. Children with difficulties in such cross-modal integration are often divided into dyslexia subtypes, based on whether their primary problem is with the written or spoken component of decoding. The present review suggests that starting in infancy, perceptions of audiovisual speech are integrated by mutual oscillatory phase-resetting between sensory cortices, and throughout development visual and auditory experiences are coupled into unified perceptions. Entirely separate subtypes are incompatible with this view. Visual or auditory deficits will invariably affect processing to some degree in both domains. It is suggested that poor auditory/visual integration may be diagnostic for both forms of dyslexia, stemming from an encoding weakness in the early cross-sensory binding of audiovisual speech. The review presents a model of dyslexia as a dysfunction of the large-scale ventral and dorsal attention networks controlling such binding. Excessive glutamatergic neuronal excitability of the attention networks by the Locus coeruleus-norepinephrine system may interfere with multisensory integration, with deleterious effects on the acquisition of reading by degrading graphene/phoneme conversion.
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Affiliation(s)
- John R Kershner
- Dept. of Applied Psychology and Human Resources University of Toronto, ON, M5S 1A1, Canada.
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15
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Dynamics of coherent activity between cortical areas defines a two-stage process of top-down attention. Exp Brain Res 2021; 239:2767-2779. [PMID: 34241642 DOI: 10.1007/s00221-021-06166-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 06/23/2021] [Indexed: 10/20/2022]
Abstract
Analysing a visual scene requires the brain to briefly keep in memory potentially relevant items of that scene and then direct attention to their locations for detailed processing. To reveal the neuronal basis of the underlying working memory and top-down attention processes, we trained macaques to match two patterns presented with a delay between them. As the above processes are likely to require communication between brain regions, and the parietal cortex is known to be involved in spatial attention, we simultaneously recorded neuronal activities from the interconnected parietal and middle temporal areas. We found that mnemonic information about features of the first pattern was retained in coherent oscillating activity between the two areas in high-frequency bands, followed by coherent activity in lower frequency bands mediating top-down attention on the relevant spatial location. Oscillations maintaining featural information also modulated activity of the cells of the parietal cortex that mediate attention. This could potentially enable transfer of information to organize top-down signals necessary for selective attention. Our results provide evidence in support of a two-stage model of visual attention where the first stage involves creating a saliency map representing a visual scene and at the second stage attentional feedback is provided to cortical areas involved in detailed analysis of the attended parts of a scene.
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16
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Power GF, Conlon EG, Zele AJ. The Functional Field of View of Older Adults is Associated With Contrast Discrimination in the Magnocellular not Parvocellular Pathway. J Gerontol B Psychol Sci Soc Sci 2021; 76:1086-1094. [PMID: 32072173 DOI: 10.1093/geronb/gbaa028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES As we age, the functional field of view (FFOV) declines and these declines predict falls and motor vehicle accidents in older adults (Owsley, C. (2013). Visual processing speed. Vision Research, 90, 52-56. doi:10.1016/j.visres.2012.11.014). To increase understanding of possible causes of this decline, the current study explored whether the FFOV in older adults is associated with the sensitivity of the magnocellular and parvocellular sub-cortical pathways. METHOD Forty-four younger (M = 27.18, SD = 5.40 years) and 44 older (M = 72.18, SD = 5.82 years) adults completed an FFOV test and the steady- and pulsed-pedestal paradigms of Pokorny and Smith (Pokorny, J., & Smith, V. C. (1997). Psychophysical signatures associated with magnocellular and parvocellular pathway contrast gain. Journal of the Optical Society of America. A, Optics, Image Science, and Vision, 14, 2477-2486. doi:10.1364/josaa.14.002477) as measures of magnocellular and parvocellular pathways, respectively. RESULTS Older adults made more FFOV errors and had higher contrast discrimination thresholds in both the steady- and pulsed-pedestal paradigms, than younger adults. FFOV errors in the younger group were not related to contrast discrimination thresholds. In multiple regression, older group FFOV errors showed a strong unique association with contrast discrimination thresholds mediated via the magnocellular, but not the parvocellular pathway. DISCUSSION We infer that reduced magnocellular pathway contrast sensitivity may contribute to reduced functional vision in older adults.
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Affiliation(s)
- Garry F Power
- School of Health and Life Sciences, Federation University, Churchill, Victoria, Australia
| | - Elizabeth G Conlon
- School of Applied Psychology, Menzies Research Institute, Griffith University, Gold Coast, Queensland, Australia
| | - Andrew J Zele
- School of Optometry and Vision Science & Institute of Health and Biomedical Innovation, Queensland University of Technology (QUT), Brisbane, Queensland, Australia
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17
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Kim J, Jung J, Nam K. Neural correlates of confusability in recognition of morphologically complex Korean words. PLoS One 2021; 16:e0249111. [PMID: 33857191 PMCID: PMC8049294 DOI: 10.1371/journal.pone.0249111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Accepted: 03/11/2021] [Indexed: 11/30/2022] Open
Abstract
When people confuse and reject a non-word that is created by switching two adjacent letters from an actual word, is called the transposition confusability effect (TCE). The TCE is known to occur at the very early stages of visual word recognition with such unit exchange as letters or syllables, but little is known about the brain mechanisms of TCE. In this study, we examined the neural correlates of TCE and the effect of a morpheme boundary placement on TCE. We manipulated the placement of a morpheme boundary by exchanging places of two syllables embedded in Korean morphologically complex words made up of lexical morpheme and grammatical morpheme. In the two experimental conditions, the transposition syllable within-boundary condition (TSW) involved exchanging two syllables within the same morpheme, whereas the across-boundary condition (TSA) involved the exchange of syllables across the stem and grammatical morpheme boundary. During fMRI, participants performed the lexical decision task. Behavioral results revealed that the TCE was found in TSW condition, and the morpheme boundary, which is manipulated in TSA, modulated the TCE. In the fMRI results, TCE induced activation in the left inferior parietal lobe (IPL) and intraparietal sulcus (IPS). The IPS activation was specific to a TCE and its strength of activation was associated with task performance. Furthermore, two functional networks were involved in the TCE: the central executive network and the dorsal attention network. Morpheme boundary modulation suppressed the TCE by recruiting the prefrontal and temporal regions, which are the key regions involved in semantic processing. Our findings propose the role of the dorsal visual pathway in syllable position processing and that its interaction with other higher cognitive systems is modulated by the morphological boundary in the early phases of visual word recognition.
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Affiliation(s)
- Jeahong Kim
- Department of Psychology, Korea University, Seoul, Republic of Korea
| | - JeYoung Jung
- School of Psychology, University of Nottingham, Nottingham, United Kingdom
| | - Kichun Nam
- Department of Psychology, Korea University, Seoul, Republic of Korea
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18
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Vidyasagar TR. Neural underpinnings of dyslexia as a disorder of visuo‐spatial attention. Clin Exp Optom 2021; 87:4-10. [PMID: 14720113 DOI: 10.1111/j.1444-0938.2004.tb03138.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2003] [Revised: 11/28/2003] [Accepted: 11/29/2003] [Indexed: 11/29/2022] Open
Abstract
For nearly 100 years, the underlying cause of dyslexia has been a matter of much debate, with widely varying viewpoints that have ranged from considering dyslexia as largely a learning disability to claims that it is essentially a perceptual defect occurring early along the visual pathway. This paper reviews some of this literature with particular reference to the studies that have implicated a defect in the afferent visual pathways in the aetiology of the disorder, then goes on to outline a neural theory of how functionally distinct parallel pathways in vision interact with each other in the process of reading and suggests how a defect in these pathways can lead to reading difficulties. Central to the proposed scheme is the suggestion that a fast-track pathway, arising from the magnocellular cells in the retina and acting through an attentional mechanism, has a gating function in spotlighting the individual letters of a text in a sequential fashion. That such gating occurs at the level of the primary visual cortex is supported by recent physiological evidence concerning attentional mechanisms.
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Affiliation(s)
- Trichur R Vidyasagar
- Department of Optometry and Vision Sciences, The University of Melbourne, Australia
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19
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Abstract
BACKGROUND Under some conditions, the time required for a visual search increases with the number of elements to be searched. It has been suggested that the overall search time reflects the duration that attention is devoted to each element multiplied by the number of elements. On this basis, it has been proposed that visual search time can be used as a measure of attention capability in dyslexic readers. However, there is evidence to suggest that the search time reflects task difficulty rather than attentional factors. Many dyslexic readers suffer from various sensory deficits. These deficits would effectively increase task difficulty for these readers. Here we use computer simulations to investigate the potential effects of sensory deficits on visual search. METHOD Visual search was modelled on a computer within the framework of signal detection theory as a matter of detecting a noisy signal from a series of noisy distractors. Sensory deficits were modelled as decreased discriminability. RESULTS Consistent with previous observations, we find that discriminability, which decreases with the number of distractors, may have a substantial effect on the search time. With regard to the effects of sensory deficits, we find that under low discriminability conditions, small sensory deficits may cause pronounced increases in search time. CONCLUSION The finding that small sensory deficits may cause pronounced increases in search time makes it specifically problematic to use visual search to test attention in individuals who suffer from sensory deficits. This applies particularly to dyslexic individuals, many of whom have been shown to suffer from visual deficiencies.
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20
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Nguyen BN, Kolbe SC, Verghese A, Nearchou C, McKendrick AM, Egan GF, Vidyasagar TR. Visual search efficiency and functional visual cortical size in children with and without dyslexia. Neuropsychologia 2021; 155:107819. [PMID: 33684399 DOI: 10.1016/j.neuropsychologia.2021.107819] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 01/28/2021] [Accepted: 03/02/2021] [Indexed: 01/01/2023]
Abstract
Dyslexia is characterised by poor reading ability. Its aetiology is probably multifactorial, with abnormal visual processing playing an important role. Among adults with normal reading ability, there is a larger representation of central visual field in the primary visual cortex (V1) in those with more efficient visuospatial attention. In this study, we tested the hypothesis that poor reading ability in school-aged children (17 children with dyslexia, 14 control children with normal reading ability) is associated with deficits in visuospatial attention using a visual search task. We corroborated the psychophysical findings with neuroimaging, by measuring the functional size of V1 in response to a central 12° visual stimulus. Consistent with other literature, visual search was impaired and less efficient in the dyslexic children, particularly with more distractor elements in the search array (p = 0.04). We also found atypical interhemispheric asymmetry in functional V1 size in the dyslexia group (p = 0.02). Reading impaired children showed poorer visual search efficiency (p = 0.01), needing more time per unit distractor (higher ms/item). Reading ability was also correlated with V1 size asymmetry (p = 0.03), such that poorer readers showed less left hemisphere bias relative to the right hemisphere. Our findings support the view that dyslexic children have abnormal visuospatial attention and interhemispheric V1 asymmetry, relative to chronological age-matched peers, and that these factors may contribute to inter-individual variation in reading performance in children.
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Affiliation(s)
- Bao N Nguyen
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Victoria, Australia.
| | - Scott C Kolbe
- Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, Victoria, Australia.
| | - Ashika Verghese
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Victoria, Australia.
| | - Christine Nearchou
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Victoria, Australia.
| | - Allison M McKendrick
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Victoria, Australia.
| | - Gary F Egan
- Monash Biomedical Imaging, Monash University, Clayton, Victoria, Australia.
| | - Trichur R Vidyasagar
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Victoria, Australia.
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21
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Manual dexterity predicts phonological decoding speed in typical reading adults. PSYCHOLOGICAL RESEARCH 2021; 85:2882-2891. [PMID: 33404906 DOI: 10.1007/s00426-020-01464-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 12/12/2020] [Indexed: 01/04/2023]
Abstract
Manual dexterity and phonological decoding involve the posterior parietal cortex, which controls location coding for visually guided actions, as well as a large fronto-cerebellar network. We studied the relationship between manual dexterity and reading ability in adult typical readers. Two measurements of manual dexterity were collected to index the procedural learning effect. A linear regression model demonstrated that phonological short-term memory, manual dexterity at time 1 and procedural learning of manual dexterity predicted phonological decoding speed. Similar results were found when left-hand dexterity at time 1 and procedural learning dexterity were entered last. The better one's phonological decoding skill was, the less fluent their manual dexterity was, suggesting a recycle from object-location to letter-location coding. However, the greater the procedural learning, the faster phonological decoding was, suggesting that larger plasticity of object-location coding was linked to better letter-location coding. An independent role of the interhemispheric connections or of the right posterior parietal cortex is also suggested.
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22
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The heritability of reading and reading-related neurocognitive components: A multi-level meta-analysis. Neurosci Biobehav Rev 2020; 121:175-200. [PMID: 33246020 DOI: 10.1016/j.neubiorev.2020.11.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 11/13/2020] [Accepted: 11/19/2020] [Indexed: 01/25/2023]
Abstract
Reading ability is a complex task requiring the integration of multiple cognitive and perceptual systems supporting language, visual and orthographic processes, working memory, attention, motor movements, and higher-level comprehension and cognition. Estimates of genetic and environmental influences for some of these reading-related neurocognitive components vary across reports. By using a multi-level meta-analysis approach, we synthesized the results of behavioral genetic research on reading-related neurocognitive components (i.e. general reading, letter-word knowledge, phonological decoding, reading comprehension, spelling, phonological awareness, rapid automatized naming, and language) of 49 twin studies spanning 4.1-18.5 years of age, with a total sample size of more than 38,000 individuals. Except for language for which shared environment seems to play a more important role, the causal architecture across most of the reading-related neurocognitive components can be represented by the following equation a² > e² > c². Moderators analysis revealed that sex and spoken language did not affect the heritability of any reading-related skills; school grade levels moderated the heritability of general reading, reading comprehension and phonological awareness.
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23
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A critical review of the cognitive and perceptual factors influencing attentional scaling and visual processing. Psychon Bull Rev 2020; 27:405-422. [PMID: 31907853 DOI: 10.3758/s13423-019-01692-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
An important mechanism used to selectively process relevant information in the environment is spatial attention. One fundamental way in which spatial attention is deployed is attentional scaling - the process of focusing attentional resources either narrowly or broadly across the visual field. Although early empirical work suggested that narrowing attention improves all aspects of visual processing, recent studies have demonstrated that narrowing attention can also have no effect or even a detrimental impact when it comes to vision that is thought to be mediated via the magnocellular pathway of the visual system. Here, for the first time, we synthesize empirical evidence measuring the behavioral effects of attentional scaling on tasks gauging the contribution of the major neural pathways of the visual system, with the purpose of determining the potential factors driving these contradictory empirical findings. This analysis revealed that attentional scaling could be best understood by considering the unique methodologies used in the research literature to date. The implications of this analysis for theoretical frameworks of attentional scaling are discussed, and methodological improvements for future research are proposed.
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24
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Ronconi L, Vitale A, Federici A, Pini E, Molteni M, Casartelli L. Altered neural oscillations and connectivity in the beta band underlie detail-oriented visual processing in autism. Neuroimage Clin 2020; 28:102484. [PMID: 33395975 PMCID: PMC7663221 DOI: 10.1016/j.nicl.2020.102484] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 08/11/2020] [Accepted: 10/22/2020] [Indexed: 11/21/2022]
Abstract
Sensory and perceptual anomalies may have a major impact on basic cognitive and social skills in humans. Autism Spectrum Disorder (ASD) represents a special perspective to explore this relationship, being characterized by both these features. The present study employed electroencephalography (EEG) to test whether detail-oriented visual perception, a recognized hallmark of ASD, is associated with altered neural oscillations and functional connectivity in the beta frequency band, considering its role in feedback and top-down reentrant signalling in the typical population. Using a visual crowding task, where participants had to discriminate a peripheral target letter surrounded by flankers at different distances, we found that detail-oriented processing in children with ASD, as compared to typically developing peers, could be attributed to anomalous oscillatory activity in the beta band (15-30 Hz), while no differences emerged in the alpha band (8-12 Hz). Altered beta oscillatory response reflected in turn atypical functional connectivity between occipital areas, where the initial stimulus analysis is accomplished, and infero-temporal regions, where objects identity is extracted. Such atypical beta connectivity predicted both ASD symptomatology and their detail-oriented processing. Overall, these results might be explained by an altered feedback connectivity within the visual system, with potential cascade effects in visual scene parsing and higher order functions.
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Affiliation(s)
- Luca Ronconi
- Faculty of Psychology, Vita-Salute San Raffaele University, Milan, Italy; IRCCS San Raffaele Scientific Institute, Milan, Italy; Theoretical and Cognitive Neuroscience Unit, Child Psychopathology Department, Scientific Institute IRCCS Eugenio Medea, Bosisio Parini, Italy.
| | - Andrea Vitale
- Theoretical and Cognitive Neuroscience Unit, Child Psychopathology Department, Scientific Institute IRCCS Eugenio Medea, Bosisio Parini, Italy
| | - Alessandra Federici
- Theoretical and Cognitive Neuroscience Unit, Child Psychopathology Department, Scientific Institute IRCCS Eugenio Medea, Bosisio Parini, Italy; IMT School of Advanced Studies Lucca, Lucca, Italy
| | - Elisa Pini
- Theoretical and Cognitive Neuroscience Unit, Child Psychopathology Department, Scientific Institute IRCCS Eugenio Medea, Bosisio Parini, Italy; Department of Psychology, University of Milano-Bicocca, Milano, Italy
| | - Massimo Molteni
- Child Psychopathology Department, Scientific Institute IRCCS Eugenio Medea, Bosisio Parini, Italy.
| | - Luca Casartelli
- Theoretical and Cognitive Neuroscience Unit, Child Psychopathology Department, Scientific Institute IRCCS Eugenio Medea, Bosisio Parini, Italy
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25
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Archer K, Pammer K, Vidyasagar TR. A Temporal Sampling Basis for Visual Processing in Developmental Dyslexia. Front Hum Neurosci 2020; 14:213. [PMID: 32733217 PMCID: PMC7360833 DOI: 10.3389/fnhum.2020.00213] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 05/11/2020] [Indexed: 11/24/2022] Open
Abstract
Knowledge of oscillatory entrainment and its fundamental role in cognitive and behavioral processing has increasingly been applied to research in the field of reading and developmental dyslexia. Growing evidence indicates that oscillatory entrainment to theta frequency spoken language in the auditory domain, along with cross-frequency theta-gamma coupling, support phonological processing (i.e., cognitive encoding of linguistic knowledge gathered from speech) which is required for reading. This theory is called the temporal sampling framework (TSF) and can extend to developmental dyslexia, such that inadequate temporal sampling of speech-sounds in people with dyslexia results in poor theta oscillatory entrainment in the auditory domain, and thus a phonological processing deficit which hinders reading ability. We suggest that inadequate theta oscillations in the visual domain might account for the many magno-dorsal processing, oculomotor control and visual deficits seen in developmental dyslexia. We propose two possible models of a magno-dorsal visual correlate to the auditory TSF: (1) A direct correlate that involves "bottom-up" magnocellular oscillatory entrainment of the visual domain that occurs when magnocellular populations phase lock to theta frequency fixations during reading and (2) an inverse correlate whereby attending to text triggers "top-down" low gamma signals from higher-order visual processing areas, thereby organizing magnocellular populations to synchronize to a theta frequency to drive the temporal control of oculomotor movements and capturing of letter images at a higher frequency.
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Affiliation(s)
- Kim Archer
- Applied Psychology and Human Factors Laboratory, School of Psychology, University of Newcastle, Newcastle, NSW, Australia
| | - Kristen Pammer
- Applied Psychology and Human Factors Laboratory, School of Psychology, University of Newcastle, Newcastle, NSW, Australia
| | - Trichur Raman Vidyasagar
- Visual and Cognitive Neuroscience Laboratory, Department of Optometry and Vision Sciences, University of Melbourne, Parkville, VIC, Australia
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
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26
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Gori M, Ober KM, Tinelli F, Coubard OA. Temporal representation impairment in developmental dyslexia for unisensory and multisensory stimuli. Dev Sci 2020; 23:e12977. [PMID: 32333455 PMCID: PMC7507191 DOI: 10.1111/desc.12977] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 12/16/2019] [Accepted: 12/24/2019] [Indexed: 11/29/2022]
Abstract
Dyslexia has been associated with a problem in visual-audio integration mechanisms. Here, we investigate for the first time the contribution of unisensory cues on multisensory audio and visual integration in 32 dyslexic children by modelling results using the Bayesian approach. Non-linguistic stimuli were used. Children performed a temporal task: they had to report whether the middle of three stimuli was closer in time to the first one or to the last one presented. Children with dyslexia, compared with typical children, exhibited poorer unimodal thresholds, requiring greater temporal distance between items for correct judgements, while multisensory thresholds were well predicted by the Bayesian model. This result suggests that the multisensory deficit in dyslexia is due to impaired audio and visual inputs rather than impaired multisensory processing per se. We also observed that poorer temporal skills correlated with lower reading skills in dyslexic children, suggesting that this temporal capability can be linked to reading abilities.
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Affiliation(s)
- Monica Gori
- U-VIP Unit for Visually Impaired People, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Kinga M Ober
- Faculty of Educational Studies, Adam Mickiewicz University, Poznan, Poland
| | - Francesca Tinelli
- Department of Developmental Neuroscience, Stella Maris Scientific Institute, Pisa, Italy
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27
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Franceschini S, Bertoni S, Puccio G, Mancarella M, Gori S, Facoetti A. Local perception impairs the lexical reading route. PSYCHOLOGICAL RESEARCH 2020; 85:1748-1756. [PMID: 32239279 DOI: 10.1007/s00426-020-01326-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 03/20/2020] [Indexed: 01/30/2023]
Abstract
Human perception of a visual scene is hierarchically organized. Such rapid, albeit coarse, global processing allows people to create a useful context in which local details can be successively allocated. Lack of the typical hierarchical global-to-local visual processing is longitudinally predictive of future reading difficulties in pre-readers, which suggests that an atypical local perception can interfere with reading skill acquisition. Global and local Navon tasks were used to induce a transient perceptual priming before a reading-aloud task. We tested the effect of an atypical local perception on lexical and sublexical reading routes in typical adult readers. Local (vs. global) priming resulted in a slower phonological access to irregular, relative to regular, words. By contrast, pseudoword reading was not affected by local (vs. global) perceptual priming. Our findings demonstrate that, in typical adult readers, local priming impairs the fast processing of the letter string useful for lexical reading.
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Affiliation(s)
- Sandro Franceschini
- Developmental and Cognitive Neuroscience Lab, Department of General Psychology, University of Padua, Via Venezia 8, 35131, Padua, Italy.
| | - Sara Bertoni
- Developmental and Cognitive Neuroscience Lab, Department of General Psychology, University of Padua, Via Venezia 8, 35131, Padua, Italy
| | - Giovanna Puccio
- Developmental and Cognitive Neuroscience Lab, Department of General Psychology, University of Padua, Via Venezia 8, 35131, Padua, Italy
| | - Martina Mancarella
- Developmental and Cognitive Neuroscience Lab, Department of General Psychology, University of Padua, Via Venezia 8, 35131, Padua, Italy
| | - Simone Gori
- Department of Human and Social Sciences, University of Bergamo, 24129, Bergamo, Italy
| | - Andrea Facoetti
- Developmental and Cognitive Neuroscience Lab, Department of General Psychology, University of Padua, Via Venezia 8, 35131, Padua, Italy
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28
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Battaglini L, Ghiani A, Casco C, Ronconi L. Parietal tACS at beta frequency improves vision in a crowding regime. Neuroimage 2019; 208:116451. [PMID: 31821867 DOI: 10.1016/j.neuroimage.2019.116451] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 11/22/2019] [Accepted: 12/06/2019] [Indexed: 10/25/2022] Open
Abstract
Visual crowding is the inability to discriminate objects when presented with nearby flankers and sets a fundamental limit for conscious perception. Beta oscillations in the parietal cortex were found to be associated to crowding, with higher beta amplitude related to better crowding resilience. An open question is whether beta activity directly and selectively modulates crowding. We employed Transcranial Alternating Current Stimulation (tACS) in the beta band (18-Hz), in the alpha band (10-Hz) or in a sham regime, asking whether 18-Hz tACS would selectively improve the perception of crowded stimuli by increasing parietal beta activity. Resting-state electroencephalography (EEG) was measured before and after stimulation to test the influence of tACS on endogenous oscillations. Consistently with our predictions, we found that 18-Hz tACS, as compared to 10-Hz tACS and sham stimulation, reduced crowding. This improvement was found specifically in the contralateral visual hemifield and was accompanied by an increased amplitude of EEG beta oscillations, confirming an effect on endogenous brain rhythms. These results support a causal relationship between parietal beta oscillations and visual crowding and provide new insights into the precise oscillatory mechanisms involved in human vision.
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Affiliation(s)
- Luca Battaglini
- Department of General Psychology, University of Padova, Italy; Neuro.Vis.U.S. Laboratory, University of Padova, Padova, Italy
| | - Andrea Ghiani
- Department of General Psychology, University of Padova, Italy
| | - Clara Casco
- Department of General Psychology, University of Padova, Italy; Neuro.Vis.U.S. Laboratory, University of Padova, Padova, Italy
| | - Luca Ronconi
- Faculty of Psychology, Vita-Salute San Raffaele University, Milan, Italy; Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy.
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Vidyasagar TR. Visual attention and neural oscillations in reading and dyslexia: Are they possible targets for remediation? Neuropsychologia 2019; 130:59-65. [DOI: 10.1016/j.neuropsychologia.2019.02.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 02/14/2019] [Accepted: 02/15/2019] [Indexed: 01/07/2023]
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Chieffi S. Dysfunction of Magnocellular/dorsal Processing Stream in Schizophrenia. CURRENT PSYCHIATRY RESEARCH AND REVIEWS 2019. [DOI: 10.2174/1573400515666190119163522] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Background:
Patients with schizophrenia show not only cognitive, but also perceptual
deficits. Perceptual deficits may affect different sensory modalities. Among these, the impairment of
visual information processing is of particular relevance as demonstrated by the high incidence of
visual disturbances. In recent years, the study of neurophysiological mechanisms that underlie
visuo-perceptual, -spatial and -motor disorders in schizophrenia has increasingly attracted the
interest of researchers.
Objective:
The study aims to review the existent literature on magnocellular/dorsal (occipitoparietal)
visual processing stream impairment in schizophrenia. The impairment of relatively early stages of
visual information processing was examined using experimental paradigms such as backward masking,
contrast sensitivity, contour detection, and perceptual closure. The deficits of late processing
stages were detected by examining visuo-spatial and -motor abilities.
Results:
Neurophysiological and behavioral studies support the existence of deficits in the
processing of visual information along the magnocellular/dorsal pathway. These deficits appear to
affect both early and late stages of visual information processing.
Conclusion:
The existence of disturbances in the early processing of visual information along the
magnocellular/dorsal pathway is strongly supported by neurophysiological and behavioral observations.
Early magnocellular dysfunction may provide a substrate for late dorsal processing impairment
as well as higher-level cognition deficits.
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Affiliation(s)
- Sergio Chieffi
- Department of Experimental Medicine, University of Campania , Italy
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Laycock R, Cutajar E, Crewther SG. Subclinical high schizotypy traits are associated with slower change detection. Acta Psychol (Amst) 2019; 195:80-86. [PMID: 30925292 DOI: 10.1016/j.actpsy.2019.03.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 02/22/2019] [Accepted: 03/18/2019] [Indexed: 11/18/2022] Open
Abstract
Patients with schizophrenia often show impairments in visual information processing that have been linked to abnormal magnocellular or dorsal stream functioning. However, such deficits are not consistently reported, possibly due to the broad symptomology inherent to schizophrenia, and/or medication effects. To avoid these latter issues this study employed visual perceptual tasks targeting magnocellular (flicker-defined form contrast threshold), dorsal stream (motion coherence, change detection) and ventral stream (form coherence) processing, and compared performance of groups of high and low sub-clinical schizotypy traits from a neurotypical population (n = 20 per group). Significantly worse performance of high compared with low schizotypy participants was only demonstrated on the change detection task that requires rapid attention acquisition and encoding of the first visual array into short term memory prior to a comparison of a second array presentation. No group differences on the other tasks were established. Given this potentially important effect is apparent in a non-clinical population, there are likely to be implications for understanding visual and attentional abnormalities in the schizophrenia spectrum more broadly.
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Affiliation(s)
- Robin Laycock
- School of Health and Biomedical Sciences, RMIT University, Melbourne, Australia; School of Psychological Sciences, La Trobe University, Melbourne 3086, Australia.
| | - Elizabeth Cutajar
- School of Psychological Sciences, La Trobe University, Melbourne 3086, Australia
| | - Sheila G Crewther
- School of Psychological Sciences, La Trobe University, Melbourne 3086, Australia
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Moulton E, Bouhali F, Monzalvo K, Poupon C, Zhang H, Dehaene S, Dehaene-Lambertz G, Dubois J. Connectivity between the visual word form area and the parietal lobe improves after the first year of reading instruction: a longitudinal MRI study in children. Brain Struct Funct 2019; 224:1519-1536. [PMID: 30840149 DOI: 10.1007/s00429-019-01855-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 02/25/2019] [Indexed: 11/30/2022]
Abstract
Shortly after reading instruction, a region in the ventral occipital temporal cortex (vOTC) of the left hemisphere, the Visual Word Form Area (VWFA), becomes specialized for written words. Its reproducible location across scripts suggests important anatomical constraints, such as specific patterns of connectivity, notably to spoken language areas. Here, we explored the structural connectivity of the emerging VWFA in terms of its specificity relative to other ventral visual regions and its stability throughout the process of reading instruction in ten children studied longitudinally over 2 years. Category-specific regions for words, houses, faces, and tools were identified in the left vOTC of each subject with functional MRI. With diffusion MRI and tractography, we reconstructed the connections of these regions at two time points (mean age ± standard deviation: 6.2 ± 0.3, 7.2 ± 0.4 years). We first showed that the regions for each visual category harbor their own specific connectivity, all of which precede reading instruction and remain stable throughout development. The most specific connections of the VWFA were to the dorsal posterior parietal cortex. We then showed that microstructural changes in these connections correlated with improvements in reading scores over the first year of instruction but not 1 year later in a subsample of eight children (age: 8.4 ± 0.3 years). These results suggest that the VWFA location depends on its connectivity to distant regions, in particular, the left inferior parietal region which may play a crucial role in visual field maps and eye movement dynamics in addition to attentional control in letter-by-letter reading and disambiguation of mirror-letters during the first stages of learning to read.
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Affiliation(s)
- Eric Moulton
- Cognitive Neuroimaging Unit U992, INSERM, CEA DRF/Institut-Joliot/NeuroSpin, Université Paris-Saclay, Université Paris-Sud, 91191, Gif/Yvette, France. .,Institut du Cerveau et de la Moelle épinière, ICM, Inserm U 1127, CNRS UMR 7225, Sorbonne Université, 75013, Paris, France.
| | - Florence Bouhali
- Institut du Cerveau et de la Moelle épinière, ICM, Inserm U 1127, CNRS UMR 7225, Sorbonne Université, 75013, Paris, France
| | - Karla Monzalvo
- Cognitive Neuroimaging Unit U992, INSERM, CEA DRF/Institut-Joliot/NeuroSpin, Université Paris-Saclay, Université Paris-Sud, 91191, Gif/Yvette, France
| | - Cyril Poupon
- CEA DRF/Institut-Joliot/NeuroSpin, UNIRS, Université Paris-Saclay, Université Paris-Sud, 91191, Gif/Yvette, France
| | - Hui Zhang
- Department of Computer Science and Centre for Medical Image Computing, University College London, Gower Street, London, WC1E 6BT, UK
| | - Stanislas Dehaene
- Cognitive Neuroimaging Unit U992, INSERM, CEA DRF/Institut-Joliot/NeuroSpin, Université Paris-Saclay, Université Paris-Sud, 91191, Gif/Yvette, France.,Collège de France, Paris, France
| | - Ghislaine Dehaene-Lambertz
- Cognitive Neuroimaging Unit U992, INSERM, CEA DRF/Institut-Joliot/NeuroSpin, Université Paris-Saclay, Université Paris-Sud, 91191, Gif/Yvette, France
| | - Jessica Dubois
- Cognitive Neuroimaging Unit U992, INSERM, CEA DRF/Institut-Joliot/NeuroSpin, Université Paris-Saclay, Université Paris-Sud, 91191, Gif/Yvette, France
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Vidyasagar TR, Levichkina E. An Integrated Neuronal Model of Claustral Function in Timing the Synchrony Between Cortical Areas. Front Neural Circuits 2019; 13:3. [PMID: 30804759 PMCID: PMC6371054 DOI: 10.3389/fncir.2019.00003] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 01/14/2019] [Indexed: 11/22/2022] Open
Abstract
It has been suggested that the function of the claustrum (CL) may be to orchestrate and integrate the activity of the different cortical areas that are involved in a particular function by boosting the synchronized oscillations that occur between these areas. We propose here a model of how this may be done, thanks to the unique synaptic morphology of the CL and its excitatory and inhibitory connections with most cortical areas. Using serial visual search as an example, we describe how the functional anatomy of the claustral connections can potentially execute the sequential activation of the representations of objects that are being processed serially. We also propose that cross-frequency coupling (CFC) between low frequency signals from CL and higher frequency oscillations in the cortical areas will be an efficient means of CL modulating neural activity across multiple brain regions in synchrony. This model is applicable to the wide range of functions one performs, from simple object recognition to reading and writing, listening to or performing music, etc.
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Affiliation(s)
- Trichur R. Vidyasagar
- Department of Optometry and Vision Science, University of Melbourne, Parkville, VIC, Australia
- Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
- Australian Research Council Centre of Excellence in Integrative Brain Function, University of Melbourne Node, Melbourne, VIC, Australia
| | - Ekaterina Levichkina
- Department of Optometry and Vision Science, University of Melbourne, Parkville, VIC, Australia
- Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, Russia
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34
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Flint S, Pammer K. It is the egg, not the chicken; dorsal visual deficits present in dyslexia are not present in illiterate adults. DYSLEXIA (CHICHESTER, ENGLAND) 2019; 25:69-83. [PMID: 30592104 DOI: 10.1002/dys.1607] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 09/03/2018] [Accepted: 12/05/2018] [Indexed: 06/09/2023]
Abstract
Some individuals with dyslexia demonstrate deficits in reading, visual attention, and visual processing which can be attributed to a functional failure of the magnocells in the visual system or in the dorsal visual pathway. The study examines the role of magno/dorsal function in dyslexic adults compared with normal, illiterate, and semi-literate readers. Coherent motion and coherent form were used in Experiment 1, and the frequency doubling illusion and static-gratings were used in Experiment 2. If a magno/dorsal deficit is demonstrated for dyslexic readers but not illiterate, semi-literate, and normal reading adults, then the deficit cannot be attributed to reading experience. Illiterate adults performed the same as normal and semi-literate readers in coherent motion and frequency doubling tasks, and all three groups performed better than the dyslexic readers. There was no difference between any of the groups in the coherent form or static grating tasks. Together, these studies show that illiterate and semi-literate adults do not demonstrate a magno/dorsal deficit that is a characteristic of some sufferers of dyslexia. Therefore, magno/dorsal deficits in dyslexia are unlikely to be a consequence of failing to learn to read but rather provides evidence to suggest a causal role for reduced visual magno/dorsal processing.
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Affiliation(s)
- Sarah Flint
- The Research School of Psychology, The Australian National University, Canberra, Australia
| | - Kristen Pammer
- The School of Psychology, The University of Newcastle, Newcastle, Australia
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35
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Lawton T, Huang MX. Dynamic cognitive remediation for a Traumatic Brain Injury (TBI) significantly improves attention, working memory, processing speed, and reading fluency. Restor Neurol Neurosci 2019; 37:71-86. [PMID: 30741708 PMCID: PMC6481540 DOI: 10.3233/rnn-180856] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
BACKGROUND In the U.S. 3.8 million people have a Traumatic Brain Injury (TBI) each year. Rapid brain training exercises to improve cognitive function after a mild TBI are needed. OBJECTIVE This study determines whether cognitive remediation by discriminating the direction a test pattern moves relative to a stationary background (movement figure-ground discrimination) improves the vision and cognitive deficits that result from a TBI, providing a paradigm shift in treatment methods. METHODS Movement-discrimination neurotraining was used to remediate low-level visual timing deficits in the dorsal stream to determine whether it improved high-level cognitive functions, such as processing speed, reading fluency, and the executive control functions of attention and working memory in four men with a TBI between the ages of 15-68. Standardized tests, as well as Magnetoencephalography (MEG) brain imaging, were administered at the beginning and end of 8-16 weeks of intervention training to evaluate improvements in cognitive skills. RESULTS Movement-discrimination cognitive neurotraining remediated both low-level visual timing deficits and high-level cognitive functioning, including selective and sustained attention, reading fluency, processing speed, and working memory for all TBI patients we studied. MEG brain imaging, using the Fast-VESTAL procedure, showed that this movement-discrimination training improved time-locked activity in the dorsal stream, attention, and executive control networks. CONCLUSIONS Remediating visual timing deficits in the dorsal stream revealed the causal role of visual movement discrimination training in improving high-level cognitive functions such as focusing and switching attention, working memory, processing speed, and reading. This study found that movement-discrimination training was very rapid and effective in remediating cognitive deficits, providing a new approach that is very beneficial for treating a mild TBI.
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Affiliation(s)
- Teri Lawton
- Department of Cognitive Neuroscience, Perception Dynamics Institute, Encinitas, CA, USA
| | - Ming-Xiong Huang
- Radiology and Research Services, VA San Diego Healthcare System, San Diego, CA, USA
- Department of Radiology, Radiology Imaging Laboratory, University of California at San Diego, San Diego, CA, USA
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36
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Tablet computer games to measure dorsal stream performance in good and poor readers. Neuropsychologia 2018; 130:92-99. [PMID: 30030193 DOI: 10.1016/j.neuropsychologia.2018.07.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 04/30/2018] [Accepted: 07/16/2018] [Indexed: 11/24/2022]
Abstract
Evidence suggests a link between deficits in visuo-spatial attention, and subsequent reading ability. However, all the research in the area thus far has been conducted using traditional, lab-based psychophysics, with very tightly controlled visual parameters. In order to take this research further, such as using visuo-spatial tasks for remediation purposes, it must be established that such tasks can be taken out of the laboratory, 'gamified', and still predict reading ability. This study aimed to determine if subtle visual deficits in poor readers could be detected outside a traditional laboratory, in relatively uncontrolled settings using portable game-like technology. Classic visual search and change detection programs, thought to rely on the visual dorsal stream, were modified to a game-like format. They were administered on a portable computer tablet within the participants' school setting. Whilst IQ predicted reading rate, visuo-spatial tasks such as visual search speed, and change detection, each accounted for unique variance in reading rate over and above IQ, age and phonological ability. These results are consistent with the visuo-spatial attention deficit hypothesis, and provide support for the development of portable computerised games that may assess and potentially target this deficit in poor readers.
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37
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Franceschini S, Mascheretti S, Bertoni S, Trezzi V, Andreola C, Gori S, Facoetti A. Sluggish dorsally-driven inhibition of return during orthographic processing in adults with dyslexia. BRAIN AND LANGUAGE 2018; 179:1-10. [PMID: 29453081 DOI: 10.1016/j.bandl.2018.01.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 10/11/2017] [Accepted: 01/29/2018] [Indexed: 06/08/2023]
Abstract
Dyslexia (D) is a neurodevelopmental reading disorder characterized by phonological and orthographic deficits. Before phonological decoding, reading requires a specialized orthographic system for parallel letter processing that assigns letter identities to different spatial locations. The magnocellular-dorsal (MD) stream rapidly process the spatial location of visual stimuli controlling visuo-spatial attention. To investigate the visuo-spatial attention efficiency during orthographic processing, inhibition of return (IOR) was measured in adults with and without D in a lexical decision task. IOR is the delay in responding to stimuli displayed in a cued location after a long cue-target interval. Only adults with D did not showed IOR effect during letter-string recognition, despite the typical left-hemisphere specialization for word identification. A specific deficit in coherent-dot-motion perception confirmed an MD-stream disorder in adults with D. Our results suggest that adults with D might develop an efficient visual word form area, but a dorsal-attentional dysfunction impairs their reading fluency.
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Affiliation(s)
- S Franceschini
- Developmental and Cognitive Neuroscience Lab, Department of General Psychology, University of Padua, Padova 35131, Italy; Child Psychopathology Unit, Scientific Institute, IRCCS Eugenio Medea, Bosisio Parini, Lecco 23842, Italy.
| | - S Mascheretti
- Child Psychopathology Unit, Scientific Institute, IRCCS Eugenio Medea, Bosisio Parini, Lecco 23842, Italy
| | - S Bertoni
- Developmental and Cognitive Neuroscience Lab, Department of General Psychology, University of Padua, Padova 35131, Italy
| | - V Trezzi
- Child Psychopathology Unit, Scientific Institute, IRCCS Eugenio Medea, Bosisio Parini, Lecco 23842, Italy
| | - C Andreola
- Child Psychopathology Unit, Scientific Institute, IRCCS Eugenio Medea, Bosisio Parini, Lecco 23842, Italy
| | - S Gori
- Child Psychopathology Unit, Scientific Institute, IRCCS Eugenio Medea, Bosisio Parini, Lecco 23842, Italy; Department of Human and Social Sciences, University of Bergamo, Bergamo 24129, Italy
| | - A Facoetti
- Developmental and Cognitive Neuroscience Lab, Department of General Psychology, University of Padua, Padova 35131, Italy; Child Psychopathology Unit, Scientific Institute, IRCCS Eugenio Medea, Bosisio Parini, Lecco 23842, Italy
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38
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Di Lollo V. Attention is a sterile concept; iterative reentry is a fertile substitute. Conscious Cogn 2018; 64:45-49. [PMID: 29482916 DOI: 10.1016/j.concog.2018.02.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 02/04/2018] [Accepted: 02/06/2018] [Indexed: 11/30/2022]
Abstract
Attention has been defined as a filter, a limited resource, a spotlight, a zoom lens, and even as a glue that binds disconnected visual features into a coherent object. Here, I claim that all of these metaphor-based explanations are circular. As such, they fail to provide adequate accounts of the phenomena they are purported to explain. In contrast, those very phenomena can be explained on the idea that perceptions emerge from iterative exchanges between cortical regions linked by two-way pathways. Processing can occur in one of two modes: feed-forward and reentrant. In feed-forward mode, the system is configured optimally for the expected input, and perception occurs on the feed-forward sweep. This form of processing corresponds to what is commonly referred to as "preattentive". If the system cannot be configured appropriately, perceptions emerge from iterative reentrant processing, which is slower, and corresponds to what is commonly referred to as "attentive".
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Affiliation(s)
- Vincent Di Lollo
- Department of Psychology, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada.
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39
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Ronconi L, Gori S, Federici A, Devita M, Carna S, Sali ME, Molteni M, Casartelli L, Facoetti A. Weak surround suppression of the attentional focus characterizes visual selection in the ventral stream in autism. NEUROIMAGE-CLINICAL 2018; 18:912-922. [PMID: 29876276 PMCID: PMC5988461 DOI: 10.1016/j.nicl.2018.02.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/26/2017] [Revised: 02/04/2018] [Accepted: 02/16/2018] [Indexed: 12/28/2022]
Abstract
Neurophysiological findings in the typical population demonstrate that spatial scrutiny for visual selection determines a center-surround profile of the attentional focus, which is the result of recurrent processing in the visual system. Individuals with autism spectrum disorder (ASD) manifest several anomalies in their visual selection, with strengths in detail-oriented tasks, but also difficulties in distractor inhibition tasks. Here, we asked whether contradictory aspects of perception in ASD might be due to a different center-surround profile of their attentional focus. In two experiments, we tested two independent samples of children with ASD, comparing them with typically developing (TD) peers. In Experiment 1, we used a psychophysical task that mapped the entire spatial profile of the attentional focus. In Experiment 2, we used dense-array electroencephalography (EEG) to explore its neurophysiological underpinnings. Experiment 1 results showed that the suppression, surrounding the attentional focus, was markedly reduced in children with ASD. Experiment 2 showed that the center-surround profile in TD children resulted in a modulation of the posterior N2 ERP component, with cortical sources in the lateral-occipital and medial/inferior temporal areas. In contrast, children with ASD did not show modulation of the N2 and related activations in the ventral visual stream. Furthermore, behavioural and neurophysiological measures of weaker suppression predicted more severe autistic symptomatology. The present findings, showing an altered center-surround profile during attentional selection, give an important insight to understand superior visual processing in autism as well as the experiencing of sensory overload.
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Affiliation(s)
- Luca Ronconi
- Developmental and Cognitive Neuroscience Lab, Department of General Psychology, University of Padua, Italy; Center for Mind/Brain Sciences (CIMeC), University of Trento, Italy; Child Psychopathology Unit, Scientific Institute IRCCS "E. Medea", Bosisio Parini, Italy.
| | - Simone Gori
- Child Psychopathology Unit, Scientific Institute IRCCS "E. Medea", Bosisio Parini, Italy; Department of Human and Social Science, University of Bergamo, Italy
| | - Alessandra Federici
- Child Psychopathology Unit, Scientific Institute IRCCS "E. Medea", Bosisio Parini, Italy
| | - Maria Devita
- Department of Human and Social Science, University of Bergamo, Italy
| | - Serena Carna
- Child Psychopathology Unit, Scientific Institute IRCCS "E. Medea", Bosisio Parini, Italy
| | - Maria E Sali
- Child Psychopathology Unit, Scientific Institute IRCCS "E. Medea", Bosisio Parini, Italy
| | - Massimo Molteni
- Child Psychopathology Unit, Scientific Institute IRCCS "E. Medea", Bosisio Parini, Italy
| | - Luca Casartelli
- Child Psychopathology Unit, Scientific Institute IRCCS "E. Medea", Bosisio Parini, Italy
| | - Andrea Facoetti
- Developmental and Cognitive Neuroscience Lab, Department of General Psychology, University of Padua, Italy; Child Psychopathology Unit, Scientific Institute IRCCS "E. Medea", Bosisio Parini, Italy.
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40
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Stein J. What is Developmental Dyslexia? Brain Sci 2018; 8:brainsci8020026. [PMID: 29401712 PMCID: PMC5836045 DOI: 10.3390/brainsci8020026] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 01/30/2018] [Accepted: 02/02/2018] [Indexed: 12/30/2022] Open
Abstract
Until the 1950s, developmental dyslexia was defined as a hereditary visual disability, selectively affecting reading without compromising oral or non-verbal reasoning skills. This changed radically after the development of the phonological theory of dyslexia; this not only ruled out any role for visual processing in its aetiology, but it also cast doubt on the use of discrepancy between reading and reasoning skills as a criterion for diagnosing it. Here I argue that this theory is set at too high a cognitive level to be explanatory; we need to understand the pathophysiological visual and auditory mechanisms that cause children's phonological problems. I discuss how the 'magnocellular theory' attempts to do this in terms of slowed and error prone temporal processing which leads to dyslexics' defective visual and auditory sequencing when attempting to read. I attempt to deal with the criticisms of this theory and show how it leads to a number of successful ways of helping dyslexic children to overcome their reading difficulties.
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Affiliation(s)
- John Stein
- Department Physiology, Anatomy & Genetics, University of Oxford, Oxford OX1 3PT, UK.
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41
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Kermani M, Verghese A, Vidyasagar TR. Attentional asymmetry between visual hemifields is related to habitual direction of reading and its implications for debate on cause and effects of dyslexia. DYSLEXIA (CHICHESTER, ENGLAND) 2018; 24:33-43. [PMID: 29214682 DOI: 10.1002/dys.1574] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 10/11/2017] [Accepted: 11/01/2017] [Indexed: 06/07/2023]
Abstract
A major controversy regarding dyslexia is whether any of the many visual and phonological deficits found to be correlated with reading difficulty cause the impairment or result from the reduced amount of reading done by dyslexics. We studied this question by comparing a visual capacity in the left and right visual hemifields in people habitually reading scripts written right-to-left or left-to-right. Selective visual attention is necessary for efficient visual search and also for the sequential recognition of letters in words. Because such attentional allocation during reading depends on the direction in which one is reading, asymmetries in search efficiency may reflect biases arising from the habitual direction of reading. We studied this by examining search performance in three cohorts: (a) left-to-right readers who read English fluently; (b) right-to-left readers fluent in reading Farsi but not any left-to-right script; and (c) bilingual readers fluent in English and in Farsi, Arabic, or Hebrew. Left-to-right readers showed better search performance in the right hemifield and right-to-left readers in the left hemifield, but bilingual readers showed no such asymmetries. Thus, reading experience biases search performance in the direction of reading, which has implications for the cause and effect relationships between reading and cognitive functions.
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Affiliation(s)
- Mojtaba Kermani
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Vic, Australia
| | - Ashika Verghese
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Vic, Australia
- School of Psychology, University of Queensland, St. Lucia, QLD, Australia
| | - Trichur R Vidyasagar
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Vic, Australia
- Melbourne Neuroscience Institute, University of Melbourne, Parkville, Vic, Australia
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42
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Franceschini S, Bertoni S, Gianesini T, Gori S, Facoetti A. A different vision of dyslexia: Local precedence on global perception. Sci Rep 2017; 7:17462. [PMID: 29234050 PMCID: PMC5727118 DOI: 10.1038/s41598-017-17626-1] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 11/29/2017] [Indexed: 01/24/2023] Open
Abstract
Individuals perceive the wor(l)d hierarchically. Firsty, the global visual scene is processed by the right hemisphere, and later, the local features are perceived by the left hemisphere. Based on this hierarchical analysis, humans evolved unique communication ability: reading. However, for about 10% of people reading acquisition is extremely difficult, they are affected by a heritable neurodevelopmental disorder called dyslexia. Differences in perceiving the wor(l)d might be one of the causes of reading disabilities. Here we show multiple causal links between the global before local perception and learning to read. Five behavioral experiments in 353 children reveal that: (i) a local before global perception characterizes three independent groups of unselected children with dyslexia; (ii) two global before local perception trainings improve reading skills in children with dyslexia; and stringently (iii) pre-reading local before global perception longitudinally predicts future poor readers. Challenging the uni-causal and left-lateralized phonological explanation of dyslexia, our results demonstrate that learning to read depends also on an efficient right neural network for the global analysis of the visual scene. These results provide new insights in learning strategies and pave the way for early identification and possible prevention programs.
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Affiliation(s)
- Sandro Franceschini
- Developmental and Cognitive Neuroscience Lab, Department of General Psychology, University of Padua, Padova, 35131, Italy. .,Child Psychopathology Unit, Scientific Institute "E. Medea", Bosisio Parini, Lecco, 23842, Italy.
| | - Sara Bertoni
- Developmental and Cognitive Neuroscience Lab, Department of General Psychology, University of Padua, Padova, 35131, Italy
| | - Tiziana Gianesini
- Neurorehabilitation Unit, Down syndrome association, Verona, 37142, Italy
| | - Simone Gori
- Child Psychopathology Unit, Scientific Institute "E. Medea", Bosisio Parini, Lecco, 23842, Italy.,Department of Human and Social Sciences, University of Bergamo, Bergamo, 24129, Italy
| | - Andrea Facoetti
- Developmental and Cognitive Neuroscience Lab, Department of General Psychology, University of Padua, Padova, 35131, Italy.,Child Psychopathology Unit, Scientific Institute "E. Medea", Bosisio Parini, Lecco, 23842, Italy
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43
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Levichkina E, Saalmann YB, Vidyasagar TR. Coding of spatial attention priorities and object features in the macaque lateral intraparietal cortex. Physiol Rep 2017; 5:5/5/e13136. [PMID: 28270589 PMCID: PMC5350164 DOI: 10.14814/phy2.13136] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 12/31/2016] [Accepted: 01/04/2017] [Indexed: 11/24/2022] Open
Abstract
Primate posterior parietal cortex (PPC) is known to be involved in controlling spatial attention. Neurons in one part of the PPC, the lateral intraparietal area (LIP), show enhanced responses to objects at attended locations. Although many are selective for object features, such as the orientation of a visual stimulus, it is not clear how LIP circuits integrate feature-selective information when providing attentional feedback about behaviorally relevant locations to the visual cortex. We studied the relationship between object feature and spatial attention properties of LIP cells in two macaques by measuring the cells' orientation selectivity and the degree of attentional enhancement while performing a delayed match-to-sample task. Monkeys had to match both the location and orientation of two visual gratings presented separately in time. We found a wide range in orientation selectivity and degree of attentional enhancement among LIP neurons. However, cells with significant attentional enhancement had much less orientation selectivity in their response than cells which showed no significant modulation by attention. Additionally, orientation-selective cells showed working memory activity for their preferred orientation, whereas cells showing attentional enhancement also synchronized with local neuronal activity. These results are consistent with models of selective attention incorporating two stages, where an initial feature-selective process guides a second stage of focal spatial attention. We suggest that LIP contributes to both stages, where the first stage involves orientation-selective LIP cells that support working memory of the relevant feature, and the second stage involves attention-enhanced LIP cells that synchronize to provide feedback on spatial priorities.
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Affiliation(s)
- Ekaterina Levichkina
- Department of Optometry & Vision Sciences, University of Melbourne, Melbourne, Australia.,Institute for Information Transmission Problems RAS, Moscow, Russia
| | - Yuri B Saalmann
- Department of Optometry & Vision Sciences, University of Melbourne, Melbourne, Australia.,Department of Psychology, University of Wisconsin - Madison, Madison, Wisconsin
| | - Trichur R Vidyasagar
- Department of Optometry & Vision Sciences, University of Melbourne, Melbourne, Australia .,Melbourne Neuroscience Institute, University of Melbourne, Australia.,Department of Anatomy & Neuroscience, University of Melbourne, Melbourne, Australia
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44
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Kunze T, Peterson ADH, Haueisen J, Knösche TR. A model of individualized canonical microcircuits supporting cognitive operations. PLoS One 2017; 12:e0188003. [PMID: 29200435 PMCID: PMC5714354 DOI: 10.1371/journal.pone.0188003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Accepted: 10/25/2017] [Indexed: 12/13/2022] Open
Abstract
Major cognitive functions such as language, memory, and decision-making are thought to rely on distributed networks of a large number of basic elements, called canonical microcircuits. In this theoretical study we propose a novel canonical microcircuit model and find that it supports two basic computational operations: a gating mechanism and working memory. By means of bifurcation analysis we systematically investigate the dynamical behavior of the canonical microcircuit with respect to parameters that govern the local network balance, that is, the relationship between excitation and inhibition, and key intrinsic feedback architectures of canonical microcircuits. We relate the local behavior of the canonical microcircuit to cognitive processing and demonstrate how a network of interacting canonical microcircuits enables the establishment of spatiotemporal sequences in the context of syntax parsing during sentence comprehension. This study provides a framework for using individualized canonical microcircuits for the construction of biologically realistic networks supporting cognitive operations.
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Affiliation(s)
- Tim Kunze
- Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- Institute of Biomedical Engineering and Informatics, Ilmenau University of Technology, Ilmenau, Germany
- * E-mail:
| | | | - Jens Haueisen
- Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- Institute of Biomedical Engineering and Informatics, Ilmenau University of Technology, Ilmenau, Germany
| | - Thomas R. Knösche
- Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
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45
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Altered Structural Connectivity of the Left Visual Thalamus in Developmental Dyslexia. Curr Biol 2017; 27:3692-3698.e4. [PMID: 29153326 DOI: 10.1016/j.cub.2017.10.034] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 09/13/2017] [Accepted: 10/11/2017] [Indexed: 11/22/2022]
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46
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Ananyev E, Penney TB, Hsieh PJB. Separate requirements for detection and perceptual stability of motion in interocular suppression. Sci Rep 2017; 7:7230. [PMID: 28775378 PMCID: PMC5543169 DOI: 10.1038/s41598-017-07805-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 06/29/2017] [Indexed: 11/09/2022] Open
Abstract
In interocular masking, a stimulus presented to one eye (the mask) is made stronger in order to suppress from awareness the target stimulus presented to the other eye. We investigated whether matching the features of the target and the mask would lead to more effective suppression (feature-selective suppression), or not (i.e., non-selective suppression). To control the temporal characteristics of the stimuli, we used a dynamic interocular mask to suppress a moving target, and found that neither matching speed nor pattern of motion led to more effective suppression. Instead, a faster target was detected faster, regardless of the mask type or speed, while a relatively slow (about 1°/s) mask was more perceptually stable (i.e., maintained suppression longer) in a non-selective fashion. While the requirement for target detectability, i.e., salience, is well characterized, relatively little attention is given to the factors that make a mask percept more perceptually stable. Based on these results, we argue that there are separate requirements for detection and perceptual stability.
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Affiliation(s)
- Egor Ananyev
- Department of Psychology, National University of Singapore, Singapore, Singapore.
| | - Trevor B Penney
- Department of Psychology, National University of Singapore, Singapore, Singapore.,LSI Programme in Neurobiology and Aging, National University of Singapore, Singapore, Singapore
| | - Po-Jang Brown Hsieh
- Neuroscience and Behavioral Disorders Program, Duke-NUS Medical School, Singapore, Singapore
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47
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Katan P, Kahta S, Sasson A, Schiff R. Performance of children with developmental dyslexia on high and low topological entropy artificial grammar learning task. ANNALS OF DYSLEXIA 2017; 67:163-179. [PMID: 27761876 DOI: 10.1007/s11881-016-0135-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2016] [Accepted: 08/16/2016] [Indexed: 06/06/2023]
Abstract
Graph complexity as measured by topological entropy has been previously shown to affect performance on artificial grammar learning tasks among typically developing children. The aim of this study was to examine the effect of graph complexity on implicit sequential learning among children with developmental dyslexia. Our goal was to determine whether children's performance depends on the complexity level of the grammar system learned. We conducted two artificial grammar learning experiments that compared performance of children with developmental dyslexia with that of age- and reading level-matched controls. Experiment 1 was a high topological entropy artificial grammar learning task that aimed to establish implicit learning phenomena in children with developmental dyslexia using previously published experimental conditions. Experiment 2 is a lower topological entropy variant of that task. Results indicated that given a high topological entropy grammar system, children with developmental dyslexia who were similar to the reading age-matched control group had substantial difficulty in performing the task as compared to typically developing children, who exhibited intact implicit learning of the grammar. On the other hand, when tested on a lower topological entropy grammar system, all groups performed above chance level, indicating that children with developmental dyslexia were able to identify rules from a given grammar system. The results reinforced the significance of graph complexity when experimenting with artificial grammar learning tasks, particularly with dyslexic participants.
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Affiliation(s)
- Pesia Katan
- Learning Disabilities Studies, School of Education, Bar-Ilan University, 52900, Ramat-Gan, Israel
| | - Shani Kahta
- Learning Disabilities Studies, School of Education, Bar-Ilan University, 52900, Ramat-Gan, Israel
| | - Ayelet Sasson
- Haddad Center for Dyslexia and Learning Disabilities, Bar Ilan University, 52900, Ramat-Gan, Israel
| | - Rachel Schiff
- Learning Disabilities Studies, School of Education, Bar-Ilan University, 52900, Ramat-Gan, Israel.
- Haddad Center for Dyslexia and Learning Disabilities, Bar Ilan University, 52900, Ramat-Gan, Israel.
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48
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Lawton T, Shelley-Tremblay J. Training on Movement Figure-Ground Discrimination Remediates Low-Level Visual Timing Deficits in the Dorsal Stream, Improving High-Level Cognitive Functioning, Including Attention, Reading Fluency, and Working Memory. Front Hum Neurosci 2017; 11:236. [PMID: 28555097 PMCID: PMC5430030 DOI: 10.3389/fnhum.2017.00236] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2017] [Accepted: 04/24/2017] [Indexed: 11/24/2022] Open
Abstract
The purpose of this study was to determine whether neurotraining to discriminate a moving test pattern relative to a stationary background, figure-ground discrimination, improves vision and cognitive functioning in dyslexics, as well as typically-developing normal students. We predict that improving the speed and sensitivity of figure-ground movement discrimination (PATH to Reading neurotraining) acts to remediate visual timing deficits in the dorsal stream, thereby improving processing speed, reading fluency, and the executive control functions of attention and working memory in both dyslexic and normal students who had PATH neurotraining more than in those students who had no neurotraining. This prediction was evaluated by measuring whether dyslexic and normal students improved on standardized tests of cognitive skills following neurotraining exercises, more than following computer-based guided reading (Raz-Kids (RK)). The neurotraining used in this study was visually-based training designed to improve magnocellular function at both low and high levels in the dorsal stream: the input to the executive control networks coding working memory and attention. This approach represents a paradigm shift from the phonologically-based treatment for dyslexia, which concentrates on high-level speech and reading areas. This randomized controlled-validation study was conducted by training the entire second and third grade classrooms (42 students) for 30 min twice a week before guided reading. Standardized tests were administered at the beginning and end of 12-weeks of intervention training to evaluate improvements in academic skills. Only movement-discrimination training remediated both low-level visual timing deficits and high-level cognitive functioning, including selective and sustained attention, reading fluency and working memory for both dyslexic and normal students. Remediating visual timing deficits in the dorsal stream revealed the causal role of visual movement discrimination training in improving high-level cognitive functions such as attention, reading acquisition and working memory. This study supports the hypothesis that faulty timing in synchronizing the activity of magnocellular with parvocellular visual pathways in the dorsal stream is a fundamental cause of dyslexia and being at-risk for reading problems in normal students, and argues against the assumption that reading deficiencies in dyslexia are caused by phonological or language deficits, requiring a paradigm shift from phonologically-based treatment of dyslexia to a visually-based treatment. This study shows that visual movement-discrimination can be used not only to diagnose dyslexia early, but also for its successful treatment, so that reading problems do not prevent children from readily learning.
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Affiliation(s)
- Teri Lawton
- Cognitive Neuroscience Research and Remediation, Perception Dynamics InstituteEncinitas, CA, USA
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Bonfiglio L, Bocci T, Minichilli F, Crecchi A, Barloscio D, Spina DM, Rossi B, Sartucci F. Defective chromatic and achromatic visual pathways in developmental dyslexia: Cues for an integrated intervention programme. Restor Neurol Neurosci 2016; 35:11-24. [PMID: 27858722 DOI: 10.3233/rnn-160636] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
PURPOSE As well as obtaining confirmation of the magnocellular system involvement in developmental dyslexia (DD); the aim was primarily to search for a possible involvement of the parvocellular system; and, furthermore, to complete the assessment of the visual chromatic axis by also analysing the koniocellular system. METHODS Visual evoked potentials (VEPs) in response to achromatic stimuli with low luminance contrast and low spatial frequency, and isoluminant red/green and blue/yellow stimuli with high spatial frequency were recorded in 10 dyslexic children and 10 age- and sex-matched, healthy subjects. RESULTS Dyslexic children showed delayed VEPs to both achromatic stimuli (magnocellular-dorsal stream) and isoluminant red/green and blue/yellow stimuli (parvocellular-ventral and koniocellular streams). To our knowledge, this is the first time that a dysfunction of colour vision has been brought to light in an objective way (i.e., by means of electrophysiological methods) in children with DD. CONCLUSION These results give rise to speculation concerning the need for a putative approach for promoting both learning how to read and/or improving existing reading skills of children with or at risk of DD. The working hypothesis would be to combine two integrated interventions in a single programme aimed at fostering the function of both the magnocellular and the parvocellular streams.
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Affiliation(s)
- Luca Bonfiglio
- Department of Translational Research on New Technologies in Medicine and Surgery, School of Physical Medicine and Rehabilitation, University of Pisa, Pisa, Italy
| | - Tommaso Bocci
- Department of Clinical and Experimental Medicine, Cisanello Neurology Unit, Pisa University Medical School, Pisa, Italy
| | - Fabrizio Minichilli
- Unit of Environmental Epidemiology, Institute of Clinical Physiology, National Council of Research, Pisa, Italy
| | - Alessandra Crecchi
- Department of Translational Research on New Technologies in Medicine and Surgery, School of Physical Medicine and Rehabilitation, University of Pisa, Pisa, Italy
| | - Davide Barloscio
- Department of Clinical and Experimental Medicine, Cisanello Neurology Unit, Pisa University Medical School, Pisa, Italy
| | - Donata Maria Spina
- Children's Neuropsychiatric Medical Facility, Local Health Authority of Viareggio (USL 12), Lido di Camaiore (LU), Italy
| | - Bruno Rossi
- Department of Translational Research on New Technologies in Medicine and Surgery, School of Physical Medicine and Rehabilitation, University of Pisa, Pisa, Italy
| | - Ferdinando Sartucci
- Department of Clinical and Experimental Medicine, Cisanello Neurology Unit, Pisa University Medical School, Pisa, Italy
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50
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Lawton T. Improving Dorsal Stream Function in Dyslexics by Training Figure/Ground Motion Discrimination Improves Attention, Reading Fluency, and Working Memory. Front Hum Neurosci 2016; 10:397. [PMID: 27551263 PMCID: PMC4976098 DOI: 10.3389/fnhum.2016.00397] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 07/25/2016] [Indexed: 11/13/2022] Open
Abstract
There is an ongoing debate about whether the cause of dyslexia is based on linguistic, auditory, or visual timing deficits. To investigate this issue three interventions were compared in 58 dyslexics in second grade (7 years on average), two targeting the temporal dynamics (timing) of either the auditory or visual pathways with a third reading intervention (control group) targeting linguistic word building. Visual pathway training in dyslexics to improve direction-discrimination of moving test patterns relative to a stationary background (figure/ground discrimination) significantly improved attention, reading fluency, both speed and comprehension, phonological processing, and both auditory and visual working memory relative to controls, whereas auditory training to improve phonological processing did not improve these academic skills significantly more than found for controls. This study supports the hypothesis that faulty timing in synchronizing the activity of magnocellular with parvocellular visual pathways is a fundamental cause of dyslexia, and argues against the assumption that reading deficiencies in dyslexia are caused by phonological deficits. This study demonstrates that visual movement direction-discrimination can be used to not only detect dyslexia early, but also for its successful treatment, so that reading problems do not prevent children from readily learning.
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Affiliation(s)
- Teri Lawton
- Perception Dynamics InstituteDel Mar, CA, USA
- Department of Computer Science and Engineering, University of California, San DiegoLa Jolla, CA, USA
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